Actually i have to got good promotion in my experience, i have lot of chances taken but i missed few mistakes, i.e my presentation problem, i have been learning a lot on my presentation actually but presentation time i have panic more. At the time i missed & forgot of my preparation.
You should learn how to control anxiety:
Breathing techniques, yoga, meditation etc can help
Just try to have a larger perspective - your presentation is definitely important but it is nothing in the bigger scheme of things, so you don't have to worry